Computer generated 3D animations are well known and are increasingly used in a wide variety of applications. For example, in motion pictures such as Jurassic Park and Twister, computer 3D animations were employed to produce scenes or portions of scenes which could not otherwise be filmed. More recently, the complete motion picture Toy Story was released wherein all scenes, objects and actors were computer generated 3D animations. In other applications, computer generated 3D animations can be used to simulate or demonstrate structures and/or systems which have not yet been built for evaluation, test and/or training purposes.
As computer 3D animation systems have become more powerful, allowing the animators to produce animations which are almost indistinguishable in many cases from reality, the systems have become more complex, involving many hundreds of tools in some cases, and generating large sets of data with which the animator must interact. To achieve an animation of a desired quality, an animator must employ at least some subset of these tools and, generally, must produce the animation in an iterative manner wherein components of the animation are defined, the output of the animation is observed, the animation is then refined with one or more tools, and the new output observed. This cycle of refining and observing can be repeated hundreds of times and generally requires the animator to interact with the very large sets of data associated with the animation and its components.
In advanced animation systems, such as SoftImage.vertline.3D V3.7 sold by the assignee of the present invention, animations are defined in terms of scenes in which objects are placed. The objects can have a series of functions curves, or F-curves, associated with them to define parameters that are animated with respect to time, or another parameter, and such animated parameters can include movements, positions, speeds, scaling, colors, etc.
For example, an object can have an F-curve defined for it which establishes its position in a scene as a function of time in the animation. The same object can have another F-curve defined for it which establishes the scaling (i.e.--size) of the object as a function of the position of the object in the animation scene. These two F-curves can be used, for example, to move an animated balloon, for which the two F-curves are defined, within a scene such that the altitude of balloon changes with time and, as the altitude of the balloon increases, it's size increases too.
To define or refine an animation, an animator must define or locate the relevant F-curves and modify them as required. For many sophisticated animations, such as those employed in the above-mentioned motion pictures, hundreds or even thousands of F-curves, or their equivalents, can be commonly employed with the objects in a scene.
While such systems provide the needed degree of control of the animation, they require a high degree of training and/or skill on the part of the animator and the amount of data can be intimidating, difficult and/or time consuming to deal with. Further, when an animation has been created, it can be difficult or even impossible to reuse portions of the animation in other animations. For example, a great deal of time can be invested in animating the walk of a bipedal character in an animation yet it can be difficult or impossible to reuse the walk for another character in the same or in a different animation as each applicable F-curve must be identified, copied and re-applied to the other character.
It is desired to have a system or method of mixing and/or compositing animation data for computer generated 3D animations which does not suffer from these disadvantages.